Sonnax 6L45/6L50/6L80/6L90 TCC Regulator Valve Kit 104740-46K

This is the Sonnax 104740-46K TCC regulator valve kit for GM 6L45, 6L50, 6L80 and 6L90 six-speed automatics. The TCC regulator valve is what meters the pressure that applies the torque converter clutch, and its bore is one of the first spots in these valve bodies to wear. Once the bore opens up, the valve can no longer seal, so hydraulic control goes inconsistent: you get no converter lockup, converter clutch slip on apply, harsh or bangy TCC engagement, a drop in fuel economy, and fluid that runs hot because the converter never fully couples. On a scan tool this often shows up alongside TCC slip readings that will not settle.

The fix is oversizing. The inboard and outboard spools on this valve are made significantly longer than stock so they ride in the unworn part of the casting bore, and the outboard shuttle valve is lengthened as well for better sealing and to keep it from cocking in the bore. The valves are hardcoat anodized aluminum so they resist the wear that killed the originals. That restores proper regulator function and a clean, consistent TCC apply on a moderately worn unit without having to replace the whole valve body.

It installs as a drop-in Zip Valve set: no reaming, no machining, no special tooling required for the valve itself. The kit contains the oversized TCC regulator valve, the shuttle valve, an end plug and the spring. If your bore is severely worn you may still need a reaming kit, but for the common moderate wear this is the direct in-car repair. Ships from the USA.